1. Field of the Disclosure
The present disclosure relates to gas turbine engines, and more particularly to heated cases housing gas turbine engine rotating components.
2. Description of Related Art
Gas turbine engines commonly include a compressor section with two or more compressor stages ordinarily sealed from the external environment. Under certain circumstances, it can become necessary to bleed compressed air from the compressor section to the external environment, typically through bleed air ducts defined through the case housing the compressor section. This can be necessary to adjust airflow and pressure ratio of fluid traversing the compressor section stages. Bleeding compressor airflow can also allow foreign material ingested by the compressor section, such as rain, ice, or hail, to be extracted from air traversing the compressor stages.
Some engine cases include ducts arranged about an annulus of the case. Valves coupled to the ducts selectively place the core interior in fluid communication with the external environment for bleeding airflow from the compressor section. Under certain operational conditions, portions of the case bounding the bleed air ducts can collect foreign material extracted from the core flow path, potentially blocking such ducts or causing the foreign material to be passed back to the compressor.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved gas turbine engine cases. The present disclosure provides a solution for this need.